r - Rvest: why does the following xpath returns empty list

Question

I am trying to extract the titles using rvest from rotten tomatoes

I use the following codes:

urlhtml<-read_html("http://www.rottentomatoes.com/browse/opening/")
df<-html_text(html_nodes(urlhtml,xpath="//*[@id='movies-collection']/div/div/div[2]/a"))

the xpath is derived from google chrome so I believe it's correct, however, it returns empty list... I can't figure out what is wrong.

Could anyone help? Much appreciated

Answer 1

Thanks everyone, it turns out like @RogerLindsj? said, I need a javascript to parse the html first and use phantomjs to cooperate R scrapping